The present invention relates to a machine for grinding sheets of glass, and in particular to a two-sided grinding machine, to which the following description refers purely by way of example.
To grind the peripheral edge of a sheet of glass, two-sided machines are used, which normally comprise a conveyor for feeding the sheets forward in succession, and two grinding units located on opposite sides of the conveyor to simultaneously grind respective lateral portions of the sheet.
Though widely used, known machines of the above type cannot be used for grinding glass sheets of all types, and in particular coated glass sheets, which, as is known, call for removing one or more peripheral portions of the coating material to glue the coated sheet to another facing sheet of glass to form insulating windows.
It is an object of the present invention to provide a machine for grinding sheets of glass, designed to provide a straightforward, low-cost solution to the above problem.
According to the present invention, there is provided a machine for grinding a coated sheet of glass comprising a sheet of glass and a layer of coating material coating the sheet of glass; the machine comprising supporting means defining a supporting surface for the sheet of glass, and at least one grinding unit comprising at least one respective first grinding wheel to grind a portion of the peripheral edge of said sheet of glass; characterized in that said grinding unit also comprises a respective second grinding wheel having an abrasive surface facing, in use, an extensive surface of said coated sheet of glass, and having a generating line parallel to said supporting surface and to said extensive surface to remove a portion of said layer of coating material.
The present invention also relates to a method of grinding coated sheets of glass.
According to the present invention, there is provided a method of grinding a coated sheet of glass comprising a sheet of glass and a layer of coating material partly coating the sheet of glass; the method comprising a first grinding step to grind a peripheral edge of the sheet of glass; and a second grinding step to remove an elongated lateral portion of said layer of coating material; characterized in that said first and said second grinding step are performed simultaneously.